Mitigating induced seismicity around depleted gas fields based on geomechanical modeling

Mitigation of induced seismicity associated with large-scale energy production from subsurface resources requires models beyond the current state of the art. In countries with long histories of conventional gas production, such as the Netherlands, issues are mainly associated with depletion-induced seismicity caused by fault reactivation due to differential compaction of reservoir compartments that are juxtaposed at faults. Geomechanical modeling approaches can be extended and integrated to better assess the occurrence of depletion-induced seismicity and provide a basis to modify operations with the aim of mitigating seismicity. Static models of fault stability and reactivation can be used to analyze the location and likelihood of fault reactivation during injection or depletion operations. Dynamic models of fault rupture and seismic wave propagation can be used to analyze the characteristics of induced seismicity from seismic source to expressions (motions) at surface or potential sensor locations. Ensemble-based optimization workflows can be used to maximize production under constraints imposed by thresholds for induced seismicity. The combination of these modeling approaches can be used to determine fault sections that are most prone to induce seismicity, analyze the fault rupture process and associated characteristics of induced seismicity, and optimize well production strategies for minimizing induced seismicity. Integrated geomechanical modeling of depletion-induced seismicity and production optimization workflows can lead to gas production strategies that maximize total gas production while minimizing seismic risk.